Opening Up the PlayStation 2 with Linux

The bout between Sony, Nintendo, and Microsoft with their video game consoles could
become even more heated when Linux enters the fray this spring. Sony will sell
online the "Linux (for PlayStation 2)"
Release 1.0 in the U.S. in May 2002. (A European version will come out that month,
too, and the Japanese version earlier in April.)

This kit will include a Linux distribution on DVD that runs on the PS2 hardware,
additional software, documentation, a 40GB hard drive, an Ethernet adapter, a USB mouse,
a USB keyboard, and a computer monitor cable. The package will cost $200. (The
PlayStation 2 is sold separately, though.)

While Linux has been brought to other consoles (such as the
SEGA Dreamcast) by hobbyist
programmers in the Linux community, this is the first distribution officially released,
sold, and supported by a major hardware manufacturer for its game console. Since the
demonstration of the kit in January this year at LinuxWorld, over four thousand people have
registered at the Linux for PlayStation 2
Community Web site. The site offers discussion forums and file space to help Linux
PS2 developers coordinate with one another on projects.

Besides the sheer geek thrill of being able to do it, there's a practical reason for
running Linux on a PlayStation 2. A lot of people expressing interest in this kit are
hobbyists looking to gain experience in developing for a major game console. The Linux PS2
distribution makes home-brew game programming and experimentation on the PS2 platform
affordable for such individuals. The only other alternative is to become a professional,
licensed developer and lease a PS2 development kit from Sony--and the professional license
and development kit cost many thousands of dollars.

The items that come with the "Linux (for PlayStation 2)" Release 1.0 kit.

(Almost) Full access to the PS2's capabilities

The PlayStation 2-specific libraries will be released under the LGPL; there are no
proprietary licenses involved. Sony's distribution of Linux is based on
Kondara Linux, which in turn is based on
Red Hat Linux. The documentation with this kit will
give all the same information about the PS2 hardware that Sony provides its licensed game
developers (but it won't give access to the system's anti-piracy mechanisms). This will
include full details on the PS2's proprietary Emotion Engine core instruction set, the
Graphic Synthesizer, and the Vector Processing Units. "The idea was to simply provide a
functional and complete distribution of Linux on the PlayStation 2, while also giving
access to the PlayStation 2's unique hardware," says Sarah Ewen, who works for Sony as
one of its Linux engineers responsible for supporting the kit.

Those interested in buying and playing around with the PS2 Linux kit should be aware of
some things before getting it: Access to the PS2's DVD drive is restricted so that only
official PlayStation discs can be read; and CD-Rs and DVD-R discs won't work in the drive.
However, the USB ports on the PS2 are standard, so some USB external CD and DVD drive
models that are supported under Linux could be used with this kit.

In terms of programming, the following graphics libraries are provided: libSDL
(a fast, 2D graphics library), mesa, and ps2gl (a simplified GL clone, which makes use of
the PlayStation 2's hardware). Ewen says, with these tools and enough effort on a
programmer's part, it is possible to create games with graphics that are comparable to
those of commercial PS2 games: "So the limitations really are few. You have almost
unfettered access to the [graphics] hardware. There is nothing stopping programmers from
coding 'right to the metal' using the Linux kit."

As for the portability of code from Linux on a PC system to the PS2, most applications
written on a PC will compile on the PlayStation 2 with little or no modification. The
significant difference is having to pass the --host option to the configure
script. The kit supports languages typical to a Linux distribution, like C, C++, Perl,
Python, Ruby, and Tcl. The only one missing is Java, although Kaffe has been ported by
others in the Linux PS2 community.

"Porting between Linux on the PC and Linux on the PS2 is very easy. Both the PC and PS2
use the same endianness, the same word sizes, et cetera," says Sam Lantinga, a software
engineer at Blizzard Entertainment (makers of the Diablo and Warcraft game franchises).
With the kit, he ported to the PS2 his Simple
DirectMedia Layer, a cross-platform library he created for handling access to graphics
and sound, that is mainly used for helping to develop Linux games. "The only kind of code
that I can think of that wouldn't run on the PS2, if it ran on a PC, would be either very
memory-intensive applications or applications like WINE that require an x86 CPU core."

Open source, open possibilities over the competition?

For Sony, there is no plan to make this kit a significant revenue source. The company
won't be advertising it through the usual methods since it doesn't want to confuse
consumers who have no interest in Linux or programming. "We're definitely not trying to
enter the desktop PC market [with the Linux PS2 kit]," says Ewen, who points out that Sony
already sells its own brand of PCs.

Regardless, there could be benefits for the company if the PS2 is seen as more than just
a game console. Lantinga predicts that this kit, with its inclusion of an Ethernet adapter
and hard drive, could spur the development of online applications and services, things
that could give the PS2 platform an edge over Microsoft's Xbox. "Linux is the natural
choice for Sony to leverage the vast amount of non-Microsoft expertise available around
the world," says Lantinga.

Then there's the advantage for Sony that more games will inevitably appear for the PS2,
thanks to this kit. Lantinga easily ported
Maelstrom to the
PlayStation 2 and played it with the console's game controllers on a television set. "That
was very cool. Any other 2D game [made with Simple DirectMedia Layer] that uses 640x480 or
lower video resolution should run just fine on the PS2," he says. "So I expect that when
the Linux kit ships in the U.S., there will be a number of games almost immediately
available for it. It should be fun."